'Castle,' 'FlashForward,' 'V': Keep 'em or kill 'em?

UPDATE: ABC on Tuesday (March 30)
picked up "Castle" for the 2010-11 season, which officially removes it from this season's bubble. As such, we've closed voting on the "Castle" poll.

Original post below.

The end of the 2009-10 TV season is approaching, and that means that a bunch of shows will be sweating out their fates over the next several weeks.

The networks, of course, will have the final say on what stays and what goes, but before then we want you to weigh in. This week,
Zap2it will present you with a list of shows that are on the bubble for renewal at each network -- those series that haven't earned a pickup for 2010-11 yet and by virtue of their ratings or other circumstances aren't exactly a shoo-in either.

Then, we want to know what you think: Should the network keep or kill them?

First up is ABC, which is doing its typical massive pilot development this season. Comedies "Modern Family," "The Middle" and "Cougar Town" have already been picked up, as has "Brothers & Sisters." "Grey's Anatomy" and "Desperate Housewives" are virtual locks, and "Private Practice" is on pretty safe ground too, as are reality franchises "Dancing With the Stars" and "The Bachelor."

That leaves just a handful of shows -- all of them hour-long dramas -- to battle for spots along with whatever new shows ABC decides to add. Here are our views as to what's on the bubble.

The case for it: Probably the most secure show on this list. It just had its most-watched episode ever (12.2 million viewers) and has been a steady performer throughout most of its second season. Fans really like the chemistry between leads Nathan Fillion and Stana Katic and love it with a "Bones"-esque intensity.

The case against it: Its ratings in the holy-grail demographic of adults 18-49 are mediocre at best -- it draws a 2.6 in the demo.

The case for it: Word is that ABC higher-ups believe in the show and really want it to succeed. It's a pretty heavily DVR'ed show, adding nearly 2 million viewers and .9 in adults 18-49 in the seven-day ratings.

The case against it: Since its big premiere in September, it has tailed off considerably. The March 18 return scored only 6.5 million viewers.

The case for it: Its first four episodes averaged a solid 12.9 million viewers and a 4.7 in the demo, both of which are in the top 25 for the season. Like "FlashForward," it adds about 2 million viewers in seven-day DVR viewing.

The case against it: Same-day ratings tailed off considerably from the premiere (14.3 million viewers) to the end of its brief fall run (9.3 million). A lot will ride on how the show performs when it returns Tuesday, March 30.
'V': Keep it or kill it?online surveysComing later this week: Bubble-show polls for CBS, FOX, NBC and The CW. Vote and share your thoughts in the comments.